Coumarin-based D–π–A dyes for efficient DSSCs: DFT and TD-DFT study of the π-spacers influence on photovoltaic properties

Research on Chemical Intermediates - A series of D–π–A architectures dyes with Coumarin-based derivatives as difluorenylaminocoumarin (DF) and diphenylaminocoumarin (DP) have been...     

A thermostated coupled apparatus for the simultaneous determination of adsorption isotherms and differential enthalpies of adsorption at high pressure and high temperature

In order to assess and improve the quality of high pressure and temperature adsorption isotherms and differential enthalpies of adsorption on microporous and mesoporous materials, a specific thermostated device comprising a differential heat flow calorimeter coupled with a home-built manometric system has been built. The differential heat flow calorimeter is a Tian Calvet Setaram C80 model which can be operated isothermally, the manometric system is a stainless steel homemade apparatus. The thermostated coupled apparatus allows measurements for pressure up to 2.5?MPa and temperature from 303 to 423?K. Reliability and reproducibility were established by measuring adsorption isotherms on a benchmark sorbent (Filtrasorb F400). A detailed experimental study of the adsorption of pure carbon dioxide and methane has been made on activated carbons (Filtrasorb F400 and EcoSorb); a new procedure for determining the differential enthalpies of adsorption based on the stepwise method is also proposed. The error in the determination of the amount adsorbed is about 3.6%, and the error in the determination of the differential enthalpies of adsorption is 4%.     

The Synthesis,Characterization and DC Electrical Conductivity of Polypyrrole‐Zirconium Complex

Polypyrrole‐zirconium complex has been synthesized by reacting 2‐amino‐3,4‐dicyano‐5‐mercaptopyrrole with zirconium nitrate in absolute ethanol under reflux for 24 h. The product has been characterized by elemental analyses, FTIR spectroscopy, in addition to thermal analysis (TGA and DSC) and its solubility has been investigated. The DC electrical conductivity variation of polypyrrole‐zirconium complex has been studied in the temperature range 300–500 K after annealing for 24 h at 100°C and doping with I₂, FeCl₃ and CuCl₂ · H₂O for comparison. An attempt has been made to interpret the DC electrical conductivity behavior and thermal properties to chain length, dopant used, polymer structure and attached groups.     

Ionic liquid behavior and high thermal stability of silver chloride nanoparticles: Synthesis and characterization

Silver chloride was found to be stable even after calcination at 650 °C for 10 h. SEM studies revealed the morphology of silver chloride as hexagonal particles. TEM studies show the size of silver chloride particles to have an average size of 6–7 nm. Thermal studies suggest that silver chloride nanoparticles behave like ionic liquid or molten salt in the range of 455–650 °C.     

Simple and Convenient Synthesis of 21‐Thioalkylether Derivatives of Methyl 16‐Prednisolone Carboxylates

The antedrug approach for corticosteroids has been described as a fundamentally sound approach for the development of safer anti‐inflammatory and anti‐asthmatic therapy. However, the derivatization of prednisolone and its congeners have been considered to be major pitfalls, because their syntheses are complicated by the presence of numerous carboxylate esters and hydroxyl functions in the steroid nucleus. A simple and direct synthesis of 21‐thioalkylether derivatives of methyl 16‐prednisolonecarboxylates is described. The 21‐mesylate of the methyl 16‐prednisolonecarboxylate and 9‐fluoro‐17‐dehydro methyl 16‐prednisolonecarboxylate were reacted with Na‐thioalkoxides to furnish the desired thioethers in good yields. A previously published method for the methanolysis of 16‐cyanoprednisolone to methylcarboxylate has been reexamined, and the conditions are explained clearly. The reaction conditions for all these reactions were critical.     

Co‐ and Counterion Effect on the Micellization Characteristics of Dodecylpyridinium Chloride

Micellization parameters, critical micelle concentration (cmc), degree of counterion dissociation (α), aggregation number (n), critical packing parameter, and hydrophobic core volume of Dodecylpyridinium chloride (DPC) micelles were determined in presence of varying concentrations of sodium chloride (NaCl), sodium acetate (SAc), sodium propionate (SPr), ethylammonium chloride (EACl), diethylammonium chloride (DEACl), tetraethylammonium chloride (TEACl), and propylammonium chloride (PACl) through conductometric investigations at 298.15 K. The resulting data suggests that both counter and coions affect the cmc values‐cmc depressing tendency of the salts varies in order PACl≈NaCl>EACl>DEACl>TEACl>SPr>SAc, while the degree of counterion dissociation is dependent on the nature and concentration range of the added salt. Increasing salt concentration increases the relative hydrophobic volume of the micelles and coion has not much effect on aggregation number.     

Inhibition effect of horehound (Marrubium vulgare L.) extract towards C38 steel corrosion in HCl solution

The corrosion inhibition properties of horehound (Marrubium vulgare L.) extract (HE) in 1 M hydrochloric acid medium was carried out using electrochemical methods (polarization curve and electrochemical impedance spectroscopy). Experiments were performed by concentration of the inhibitor and temperature effect. The results showed variation in inhibition performance of this plant extract. The Langmuir model was tested to describe the adsorption behavior of the inhibitor on the C38 steel surface. Some thermodynamic functions of dissolution processes were also determined.